HA System Control for 6500 sqft New Construction House

[nexus99]

I'll give you an example of an early project I did for a friend. The house had a few security sensors and speakers already wired, at least 200 wires had to be retrofitted. It cost around 9K in hardware and would have been done in a 80 hour week if I was working on it full time. If it was a job I was hired for, I'd have to be a little bit neater and spend a lot of time discussing options, iterating through software interfaces, etc, so maybe 120 hours or more depending on how knowledgeable/helpful the homeowner is with pulling wires. The labor adds up fast, especially in a difficult house. My friend was lucky, no charge for time and he helped out so we got it all done super fast.

Elk M1 for security and basic automation.
22 RadioRA loads for lighting.
Russound CAM6.6 6-zone audio distribution system.
18 automated retrofit dampers and zone control for single furnace.
3 communicating thermostats and new wiring.
CQC for touchscreen interfaces and additional automation
2 security cameras and DVR
Basic structured wiring system demolition and install

Could you talk a little bit about the dampers? I would love to add some zone control into my HVAC system. I am in SoCal. Have a gas furnace and an AC unit piping through the same vents. I will control via HAI thermo soon. Having zones would be SO wonderful.

 

[signal15]

I'll give you an example of an early project I did for a friend. The house had a few security sensors and speakers already wired, at least 200 wires had to be retrofitted. It cost around 9K in hardware and would have been done in a 80 hour week if I was working on it full time. If it was a job I was hired for, I'd have to be a little bit neater and spend a lot of time discussing options, iterating through software interfaces, etc, so maybe 120 hours or more depending on how knowledgeable/helpful the homeowner is with pulling wires. The labor adds up fast, especially in a difficult house. My friend was lucky, no charge for time and he helped out so we got it all done super fast.

Elk M1 for security and basic automation.
22 RadioRA loads for lighting.
Russound CAM6.6 6-zone audio distribution system.
18 automated retrofit dampers and zone control for single furnace.
3 communicating thermostats and new wiring.
CQC for touchscreen interfaces and additional automation
2 security cameras and DVR
Basic structured wiring system demolition and install

Could you talk a little bit about the dampers? I would love to add some zone control into my HVAC system. I am in SoCal. Have a gas furnace and an AC unit piping through the same vents. I will control via HAI thermo soon. Having zones would be SO wonderful.

I don't think you can just willy-nilly add zoning. Assume that only one room might request heating/cooling. All dampers are closed except for that one. The static pressure in the system will be considerably higher than normal, and will eventually burn out your fan if this happens often. If the zoning is to sections of the house rather than individual rooms, you don't have to worry about this as much. But the better zoning systems have static pressure sensors before and after the furnace to continually monitor what's happening.

That said, I am going to put in some automatic dampers since my basement is unfinished. I'll worry about the control of them and potential issues when I go to hook them all up.

 

[DavidL]

signal15, generally a bypass valve is used to minimize the chance that too many zones are closed putting to much air pressure against the fan. Good logic in controlling the ducts is first line of defense.

Also note that most dampers reduce the total cfm a given duct can deliver, even when wide open. Installers I know, upscale the duct at the damper to minimize that effect.

 

[icellama21]

You will need to do some research before adding dampers. Typical advice is to make sure that the ducting(total CFM that the ducting supports) for each zone is at least 2/3 of the CFM of the air handler. If the CFM for the smallest zone is less, add bypass. But this is general, there are too many variables. If you care about your furnace then do some research and consult an HVAC guy. Here is what you basically need to do:

1) Divide your vents/registers into zones. Calculate the CFM for each zone(ex 2 6" round pipe + 3 8" round pipe registers) and compare it to the CFM for your air handler.

2) Install dampers. You can use retrofit dampers(go into the round duct as it is), new dampers(have to separate the duct) or trunk dampers(used to control airflow to multiple registers).

3) Add some bypass. Typical ways are a dump zone(a few vents in an area of the house you don't care about that dump the excess air, preferably has a return air duct in this area too), direct bypass(some kind of bariometric sensor, static pressure weight, etc between the supply and return at the furnace) or setting each zone damper to only close 80-90% of the way to allow for leakage.

4) Install proper zone control panel with a temperature sensor to shut down furnace if it gets too hot/cold due to inadequate airflow or excessive bypass. Hook your thermostats and damper controls to the zone control panel.

5) Connect your communicating thermostats to your automation system.

6) Test it a lot before running it when not at home, etc.